text: In NMR spectroscopy, receptivity refers to the relative detectability of a particular element.  Some elements are easily detected, some less so.  The receptivity is a function of the abundance of the elements NMR-responsive isotope and that isotopes gyromagnetic ratio (or equivalently, the nuclear magnetic moment).  Some isotopes, tritium for example, have large gyromagnetic ratios but low abundance.  Other isotopes, for example Rh, are highly abundant but have low gyromagnetic ratios. Widely used NMR spectroscopies often focus on highly receptive elements: H, F, and P.